Use of calcium oxide as a water scavenger in solar applications

ABSTRACT

A solar module includes an edge sealant. The sealant composition includes an unsaturated reactive polyolefin, an olefmic polymer, a silane modified polyolefin, inert fillers, calcium oxide, and aging resistors. These components are balanced to produce a sealant having desirable sealing characteristics, high weatherability, desired rheology, low conductivity, and good water absorption.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application claims the benefit of U.S. Provisional PatentApplication No. 61/251,527, filed on Oct. 14, 2009, and is acontinuation-in-part of co-pending U.S. patent application Ser. No.12,679,250, filed on Mar. 19, 2010, which claims priority toInternational Application No. PCT/DE/2008/001564, filed on Sep. 22,2008, which claims priority to German priority document DE/10 2007 045104.2, filed on Sep. 20, 2007. The contents of the above applicationsare incorporated herein by reference in their entirety.

FIELD

The present invention relates to use of calcium oxide as a waterscavenger in edge sealant formulations for solar modules.

BACKGROUND

Photovoltaic solar panels or modules generally include a photovoltaicdevice that is laminated and/or sandwiched between a plurality oflayers. The majority of photovoltaic devices are rigid wafer-basedcrystalline silicon cells or thin film modules having cadmium telluride(Cd—Te), amorphous silicon, or copper-indium-diselenide (CuInSe₂)deposited on a substrate. The thin film solar modules may be eitherrigid or flexible. Flexible thin film cells and modules are created bydepositing the photoactive layer and any other necessary substance on aflexible substrate. Photovoltaic devices are connected electrically toone another and to other solar panels or modules to form an integratedsystem.

The efficiency of photovoltaic solar panels is lessened by intrusion ofmoisture. One effective method of lessening this transfer of moisturefrom the environment to the interior, moisture sensitive portion of thesolar module is to use edge sealants. These edge sealants have theproperty of having a low rate of moisture vapor transmission, or MVT.

An additional method for reducing the rate of moisture transmission isthrough use of a desiccant material. One such class of desiccantmaterials is molecular sieves. Molecular sieves are comprised ofmaterials containing tiny pores of a precise and uniform size that areused as an adsorbent. Molecules of water are small enough to passthrough the pores and are adsorbed within the molecular sieve material.A typical molecular sieve can adsorb water up to 22% of its own weight.Examples of molecular sieves include, but are not limited to,aluminosilicate minerals, clays, porous glasses, microporous charcoals,zeolites, active carbons, or synthetic compounds that have openstructures through which small molecules, such as water can diffuse.

However, the absorption of moisture by molecular sieves is reversible.That is, moisture held within a molecular sieve can be released. Someversions of molecular sieves attempt to better trap moisture byincluding additional compounds or elements that react with the water.

Other materials can be used as desiccants. These include silica gel,calcium sulfate (offered for sale as Drierite™), and calcium chloride.These desiccants react with water, but in a reversible way. Thus some ofthe moisture can be released after being absorbed, adsorbed or reacted.

Another class of materials that can remove moisture from surroundingsinclude water scavengers. Unlike standard desiccants, water scavengersreact with water in a manner that is not reversible under the conditionsthat the product experiences in its normal lifetime. However, waterscavengers are caustic compounds that are corrosive. Accordingly, waterscavengers have not been used in solar module applications due to thecaustic nature of the compound. Therefore, there is a need in the artfor a sealant in solar modules that incorporates a water scavenger thatdoes not release water and that does not corrode the sealant over thelifetime of the solar module and that provides improved water absorptionover desiccant materials.

SUMMARY

The present invention provides a photovoltaic solar module with an edgeseal. The edge sealant incorporates calcium oxide as a water scavengerin place of a desiccant, such as a molecular sieve. The calcium oxidewithin the edge sealant has improved water absorption characteristicsover conventional desiccants. In addition, the calcium oxide does notcorrode or reduce the effectiveness of the edge sealant over time.

In one example of the present invention, a sealant composition includesan olefinic polymer, a silane modified polyolefin, at least one filler,a carbon black, a calcium oxide included in an amount greater than about2.5% by weight of the total composition, and at least one agingresistor.

In another example of the present invention, the sealant compositionfurther includes a molecular sieve in an amount greater than about 2.5%by weight of the total composition.

In another example of the present invention, the sealant compositionexhibits a water break through time of greater than 5 hr and a steadystate moisture vapor transmission rate of less than 40 g·m2/day for a0.030 inch thick sample of the sealant composition tested at 85 C and100% relative humidity.

In another example of the present invention, the sealant compositionexhibits a water break through time of greater than 10 hr and a steadystate moisture vapor transmission rate of less than 30 g·m2/day for a0.030 inch thick sample of the sealant composition tested at 85 C and100% relative humidity.

In another example of the present invention, a combination of thecalcium oxide and the molecular sieve is included in an amount greaterthan about 10% by weight and the sealant composition exhibits a waterbreak through time of greater than 5 hr and a steady state moisturevapor transmission rate of less than 40 g·m2/day for a 0.030 inch thicksample of the sealant composition tested at 85 C and 100% relativehumidity.

In another example of the present invention, a combination of thecalcium oxide and the molecular sieve is included in an amount greaterthan about 10% by weight and the sealant composition exhibits a waterbreak through time of greater than 10 hr and steady state moisture vaportransmission rate of less than 30 g·m2/day for a 0.030 inch thick sampleof the sealant composition tested at 85 C and 100% relative humidity.

In another example of the present invention, the sealant compositionfurther includes at least one of a clay, a calcium sulfate, and a silicagel. The sealant composition exhibits exhibit a water break through timeof greater than 5 hr and a steady state moisture vapor transmission rateof less than 40 g·m2/day for a 0.030 inch thick sample of the sealantcomposition tested at 85 C and 100% relative humidity.

In another example of the present invention, the sealant compositionfurther includes at least one of a clay, a calcium sulfate, and a silicagel. A combination of the calcium oxide, the molecular sieve, and thesealant composition exhibits a water break through time of greater than10 hr and steady state moisture vapor transmission rate of less than 30g·m2/day for a 0.030 inch thick sample of the sealant composition testedat 85 C and 100% relative humidity.

In yet another example of the present invention, a combination of thecalcium oxide and the molecular sieve is included in an amount fromabout 10% to about 40% by weight of the total composition.

In yet another example of the present invention, a combination of thecalcium oxide and the molecular sieve is included in an amount fromabout 20% to about 40% by weight of the total composition.

In yet another example of the present invention, combination of thecalcium oxide and the molecular sieve is included in an amount fromabout 25% to about 35% by weight of the total composition.

In yet another example of the present invention, the olefinic polymer isincluded in an amount from about 30% to about 60% by weight of the totalcomposition, the silane modified polyolefin is included in an amountfrom about 10% to about 25% by weight of the total composition, thecarbon black is included in an amount from about 2% to about 20% byweight of the total composition, the filler is included in an amountfrom about 20% to about 60% by weight of the total composition, thecalcium oxide is included in an amount from about 2.5% to about 25% byweight of the total composition, and the aging resistor is included inan amount from 0% to about 2% by weight of the total composition.

In yet another example of the present invention, the olefinic polymer isincluded in an amount from about 20% to about 40% by weight of the totalcomposition, the silane modified polyolefin is included in an amountfrom about 10% to about 20% by weight of the total composition, acombination of the carbon black and the filler is included in an amountfrom about 30% to about 40% by weight of the total composition, thecalcium oxide is included in an amount from about 10% to about 30% byweight of the total composition, and the aging resistor is included inan amount from 0% to about 2% by weight of the total composition.

In yet another example of the present invention, the sealant compositionfurther includes a molecular sieve included in an amount from about 2.5%to about 25% by weight of the total composition.

In yet another example of the present invention, the sealant compositionexhibits less than about 15 gm/((m̂2)*day) moisture vapor transmissionrate at steady state for a 0.030 inch thick sample of the sealantcomposition tested at 85 C and 100% relative humidity.

In yet another example of the present invention, the sealant includesbalanced properties that keep swelling of the sealant to a predeterminedamount upon reaction of the calcium oxide with water.

In yet another example of the present invention, the calcium oxide doesnot substantially react with or corrode other components of the sealant.

In yet another example of the present invention, the olefinic polymerincludes at least one of a polyethylene, a polypropylene, a polybutene,a polyisobutene, a butyl rubber (polyisobutene-isoprene), styrene blockcopolymers, and modified forms of styrene block copolymers, wherein theolefinic polymers have a Number average molecular weight of 100-700,000Da. The silane modified polyolefins include at least one of an amorphouspoly alpha olefin, a silane grafted PE, a moisture curing catalyst, analkoxy silane, and an amino silane. The fillers include at least one ofa ground chalk, a precipitated chalk, a silicate, a silicon oxide,CaCO3, Ca(OH)2, and titanium dioxide. The silicate is selected from thegroup comprising talc, kaolin, mica, silicon oxide, silicas, and calciumor magnesium silicates. The aging resistors include at least one ofhindered phenols, hindered amines, thioethers, mercapto compounds,phosphorous esters, benzotriazoles, benzophenones, and antizonants.

DRAWINGS

FIG. 1 is a top view of an embodiment of a solar module having a borderseal composition according to the principles of the present invention;

FIG. 2 is a cross-sectional view of a portion of an embodiment of asolar module having a border seal composition according to the presentinvention;

FIG. 3 is a graph of moisture vapor transmission rate with time of asealant composition that includes calcium oxide at 20% by weight; and

FIG. 4 is a graph of moisture vapor transmission rate with time of asealant composition that includes type 3A molecular sieves at 20% byweight.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses.

With reference to FIGS. 1 and 2, an exemplary solar module employing asealant composition according to the principles of the present inventionis generally indicated by reference number 10. The solar module 10 maytake various forms without departing from the scope of the presentinvention and generally includes at least one photovoltaic cell 12located within a chamber 13 defined by a first substrate 14 and a secondsubstrate 16. The solar module 10, however, may be a thermoelectricsolar module, hybrid solar module, or other light collecting assemblywithout departing from the scope of the present invention. While aplurality of photovoltaic cells 12 are illustrated, it should beappreciated that any number of photovoltaic cells 12 may be employed.

The photovoltaic cell 12 is operable to generate an electrical currentfrom sunlight striking the photovoltaic cell 12. Accordingly, thephotovoltaic cell 12 may take various forms without departing from thescope of the present invention. For example, the photovoltaic cell 12may be a thin film cell with a layer of cadmium telluride (Cd—Te),amorphous silicon, or copper-indium-diselenide (CuInSe₂). Alternatively,the photovoltaic cell 12 may be a crystalline silicon wafer embedded ina laminating film or gallium arsenide deposited on germanium or anothersubstrate. Other types of photovoltaic devices 12 that may be employedinclude organic semiconductor cells having conjugate polymers as well asdye-sensitized metal oxides including wet metal oxides and solid metaloxides. The photovoltaic device 12 may be either rigid or flexible. Thephotovoltaic cells 12 are linked either in series or in parallel orcombinations thereof. The current produced by the photovoltaic cells 12are communicated via bus bars or other conductive materials or layers towires or lead lines 15 that exit the solar module 10. The lead lines 15communicate with a junction box 17 in order to distribute the electricalcurrent generated by the solar module 10 to a power circuit.

The first substrate 14, or front panel, is formed from a materialoperable to allow wavelengths of sunlight to pass therethrough. Forexample, the first substrate 14 is glass or a plastic film such aspolyvinylflouride. The second substrate 16, or back panel, is selectedto provide additional strength to the solar module 10. For example, thesecond substrate 16 is a plastic such as fluorinated ethylene-propylenecopolymer (FEP), poly(ethylene-co-tetrafluoroethylene) (ETFE),polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF),poly(tetrafluoroethylene) (PTFE) and combinations of these with otherpolymeric materials.

The photovoltaic cells 12 are encapsulated by a laminate layer 19 thatis preferably a cross-linkable ethyl vinyl acetate (EVA). However, itshould be appreciated that other laminates or encapsulants may beemployed without departing from the scope of the present invention. Thelaminate layer 19 is used to partially encapsulate the photovoltaicdevice 12 to protect the photovoltaic device 12 from contamination andfrom the environment.

A border or edge seal 18 is located near an edge of the solar module 10between the first substrate 14 and the second substrate 16. The borderseal 18 may have various widths. In addition, a second border seal (notshown) may also be included. The second border seal may be comprised of,for example, for example, a silicone, a MS polymer, a SilanatedPolyurethane, a butyl, or a polysulfide. The border seal 18 is operableto seal the laminate layer 19 and photovoltaic devices 12. The borderseal 18 must have sufficient weatherability to withstand exposure tooutside environments including prolonged ultra-violet radiationexposure, have low moisture vapor transmission (MVT), and have lowconductivity. The border seal 20 is comprised of a sealant compositionhaving the unique characteristics of high weatherability with lowconductivity and MVT, as well as the ability to permanently absorb andreact with water during normal operating conditions of the solar module10.

The sealant composition of the border seal 18 includes an unsaturatedreactive polyolefin, an olefinic polymer, a silane modified polyolefin,inert fillers, calcium oxide, and aging resistors. These components arebalanced to produce a sealant having desirable sealing characteristics,high weatherability, desired rheology, low conductivity, and good waterabsorption.

Calcium oxide reacts with water to form calcium hydroxide, according tothe equation:

CaO+H₂O→Ca(OH)₂  (1)

When heated to 512° C., the partial pressure of water in equilibriumwith calcium hydroxide reaches 101 kPa and decomposes into calcium oxideand water. Since solar modules do not experience such high temperatureconditions, this reverse reaction does not occur to any appreciableextent.

The calcium oxide adsorbs a much greater amount of water vapor at a verylow relative humidity than other materials. Calcium oxide is mosteffective where a low critical relative humidity is necessary, and wherethere is a high concentration of water vapor present. Calcium oxideremoves water from the environment very slowly, often taking days toreach its maximum capacity. In addition, calcium oxide has a low watercapacity at room temperature and humidity. As the calcium oxide adsorbsmoisture, it swells. Accordingly, the sealant composition must havebalanced properties to account for any swelling during use. Theproperties are balanced by, for example, adjusting the amount of calciumoxide in the composition. The density of calcium oxide is 3.25-3.38g/mL, and the density of calcium hydroxide is 2.24 g/mL, according tothe CRC Handbook of Chemistry and Physics, 60^(th) edition. Therefore,theoretically, there is a limit as to how much calcium oxide may beincorporated into an edge sealant formulation. However, no difficultieshave been observed over the incorporation range tested.

The use of calcium oxide having about a three micron median particlesize results in less free volume as compared to the typically largerparticle sizes of other desiccants. As a result, the steady statemoisture vapor transmission rate (after about 150 hours in FIGS. 3 and4) of the exhausted calcium oxide is lower, at about 14 g/m*day, thancompositions containing other exhausted desiccants and molecular sieveswith larger median particle sizes, as can be seen in FIG. 3 and FIG. 4.FIGS. 3 and 4 show moisture vapor rate test results with time for asimilar composition with different desiccants. FIG. 3 shows the resultsfrom a sealant composition containing calcium oxide at 20% by weight andFIG. 4 shows a sealant composition containing type 3A molecular sievesat 20% by weight. The tests were performed on 30 mil samples at 85 C and100% RH in a Mocon model permatran-w 3/33. The samples were pre-driedfor 90 h under N2 purge before water was added to test the MVTR. Asdiscussed above, the composition containing calcium oxide exhibits alower steady state MVTR when compared with the composition containingmolecular sieves at least partially due to the small particle size ofcalcium oxide.

In addition to steady state MVTR, FIGS. 3 and 4 show the break throughtimes associated with use of calcium oxide over molecular sieves. Breakthrough time is the amount of time it takes to reach 5% of the steadystate MVTR value after the initial 90 hour predrying phase is complete.As seen by FIG. 3, the breakthrough time for the composition containingcalcium oxide is about 9 hours and the break through time for thecomposition containing the molecular sieve shown in FIG. 4 is about 20hours.

In addition, one liter of water combines with approximately 3.1 kg ofcalcium oxide to give calcium hydroxide plus 3.54 MJ of energy. Thelevel of heat generated by the exothermic reaction between calcium oxideand water discourages the use of calcium oxide as a water scavenger inedge seals. However, since the reaction occurs so slowly, the heatgeneration is imperceptible during use in an edge seal, and thus calciumoxide is a satisfactory edge seal water scavenger.

Calcium oxide is corrosive and can theoretically react with othercomponents within an edge seal and within a solar module. However,within edge seals in solar modules with the present composition, nocorrosive effects manifest.

In addition, calcium oxide can be combined with molecular sieves tofurther increase the moisture trapping ability of the edge sealant.

In order that the invention may be more readily understood, reference ismade to the following example which is intended to illustrate theinvention, but not limit the scope thereof:

Example 1

Material Wt % Olefinic polymer less than 60 Silane modified polyolefinsless than 30 C black less than 30 Inert fillers less than 60 CaO lessthan 25 Aging Resistors less than 3

Example 2

Material Wt % Olefinic polymer less than 60 Silane modified polyolefinsless than 30 C black less than 30 Inert fillers less than 60 MolecularSieves less than 25 Aging Resistors less than 3

Example 3

Material Wt % Olefinic polymer less than 60 Silane modified polyolefinsless than 30 C black less than 30 Inert fillers less than 60 CaO lessthan 25 Molecular Sieves less than 25 Aging Resistors less than 3

Example 4

Material Wt % Olefinic polymer less than 60 Silane modified polyolefinsless than 25 C black less than 20 Inert fillers less than 60 MolecularSieves less than 25 CaO less than 25 Aging Resistors less than 3

Example 5

Material Wt % Olefinic polymer 30 to 60 Silane modified polyolefins 10to 25 C black 2 to 20 Inert fillers 20 to 60 Molecular sieves less than25 CaO less than 25 Aging resistor less than 2

Example 6

Material Wt % Olefinic polymer 30 to 60 Silane modified polyolefins 10to 25 C black 2 to 20 Inert fillers 20 to 60 CaO less than 25 Agingresistor less than 2

Example 7

Material Wt % Olefinic polymer 30 to 40 Silane modified polyolefins 10to 20 C black and inert fillers 30 to 40 CaO and molecular sieves 25 to35 Aging resistor less than 2

The olefinic polymers may include, for example, polyethylene,polypropylene, polybutene, polyisobutene, butyl rubber(polyisobutene-isoprene), styrene block copolymers, and modified formsof styrene block copolymers. The olefinic polymers have number averagemolecular weights of 100-700,000 Da, and preferably have number averagemolecular weights of 100-300,000 Da.

The silanes may include, for example, DFDA-5451NT (silane grafted PEavailable from Dow Chemical of Midland, Mich.), DFDA-5481 NT (moisturecuring catalyst from Dow Chemical of Midland, Mich.), amorphous polyalpha olefins (such as but not restricted to VESTOPLAST 206 andVESTOPLAST 2412 available from Evonik Degussa GmbH of Marl, Germany),alkoxy silanes, and amino silanes.

The inert fillers may include, for example, ground and precipitatedchalks, silicates, silicon oxides, C black, CaCO3, Ca(OH)2, and titaniumdioxide. The silicates may include, for example, talc, kaolin, mica,silicon oxide, silicas, and calcium or magnesium silicates. The agingresistors may include, for example, hindered phenols, hindered amines,thioethers, mercapto compounds, phosphorous esters, benzotriazoles,benzophenones, and antizonants.

The description of the invention is merely exemplary in nature andvariations that do not depart from the gist of the invention areintended to be within the scope of the invention. Such variations arenot to be regarded as a departure from the spirit and scope of theinvention.

1. A sealant composition comprising: an olefinic polymer; a silanemodified polyolefin; at least one filler; a carbon black; a calciumoxide included in an amount greater than about 2.5% by weight of thetotal composition; and at least one aging resistor.
 2. The sealantcomposition of claim 1 further including a molecular sieve included inan amount greater than about 2.5% by weight of the total composition. 3.The sealant composition of claim 2 wherein the sealant compositionexhibits a water break through time of greater than 5 hr and a steadystate moisture vapor transmission rate of less than 40 g·m2/day for a0.030 inch thick sample of the sealant composition tested at 85 C and100% relative humidity.
 4. The sealant composition of claim 2 whereinthe sealant composition exhibits a water break through time of greaterthan 10 hr and a steady state moisture vapor transmission rate of lessthan 30 g·m2/day for a 0.030 inch thick sample of the sealantcomposition tested at 85 C and 100% relative humidity.
 5. The sealantcomposition of claim 2 wherein a combination of the calcium oxide andthe molecular sieve is included in an amount greater than about 10% byweight and the sealant composition exhibits a water break through timeof greater than 5 hr and a steady state moisture vapor transmission rateof less than 40 g·m2/day for a 0.030 inch thick sample of the sealantcomposition tested at 85 C and 100% relative humidity.
 6. The sealantcomposition of claim 2 wherein a combination of the calcium oxide andthe molecular sieve is included in an amount greater than about 10% byweight and the sealant composition exhibits a water break through timeof greater than 10 hr and steady state moisture vapor transmission rateof less than 30 g·m2/day for a 0.030 inch thick sample of the sealantcomposition tested at 85 C and 100% relative humidity.
 7. The sealantcomposition of claim 2 further including at least one of a clay, acalcium sulfate, and a silica gel, and wherein the sealant compositionexhibits exhibit a water break through time of greater than 5 hr and asteady state moisture vapor transmission rate of less than 40 g·m2/dayfor a 0.030 inch thick sample of the sealant composition tested at 85 Cand 100% relative humidity.
 8. The sealant composition of claim 2further including at least one of a clay, a calcium sulfate, and asilica gel, and wherein a combination of the calcium oxide, themolecular sieve, and the sealant composition exhibits a water breakthrough time of greater than 10 hr and steady state moisture vaportransmission rate of lesser than 30 g·m2/day for a 0.030 inch thicksample of the sealant composition tested at 85 C and 100% relativehumidity.
 9. The sealant composition of claim 2 wherein a combination ofthe calcium oxide and the molecular sieve is included in an amount fromabout 10% to about 40% by weight of the total composition.
 10. Thesealant composition of claim 2 wherein a combination of the calciumoxide and the molecular sieve is included in an amount from about 20% toabout 40% by weight of the total composition.
 11. The sealantcomposition of claim 2 wherein a combination of the calcium oxide andthe molecular sieve is included in an amount from about 25% to about 35%by weight of the total composition.
 12. The sealant composition of claim1 wherein the olefinic polymer is included in an amount from about 30%to about 60% by weight of the total composition, the silane modifiedpolyolefin is included in an amount from about 10% to about 25% byweight of the total composition, the carbon black is included in anamount from about 2% to about 20% by weight of the total composition,the filler is included in an amount from about 20% to about 60% byweight of the total composition, the calcium oxide is included in anamount from about 2.5% to about 25% by weight of the total composition,and the aging resistor is included in an amount from 0% to about 2% byweight of the total composition.
 13. The sealant composition of claim 1wherein the olefinic polymer is included in an amount from about 20% toabout 40% by weight of the total composition, the silane modifiedpolyolefin is included in an amount from about 10% to about 20% byweight of the total composition, a combination of the carbon black andthe filler is included in an amount from about 30% to about 40% byweight of the total composition, the calcium oxide is included in anamount from about 10% to about 30% by weight of the total composition,and the aging resistor is included in an amount from 0% to about 2% byweight of the total composition.
 14. The sealant composition of claim 13further including a molecular sieve included in an amount from about2.5% to about 25% by weight of the total composition.
 15. The sealantcomposition of claim 1 wherein the sealant composition exhibits lessthan about 15 gm/((m̂2)*day) moisture vapor transmission rate at steadystate for a 0.030 inch thick sample of the sealant composition tested at85 C and 100% relative humidity.
 16. The sealant composition of claim 1wherein the sealant composition includes balanced properties that keepsswelling of the sealant to a predetermined amount upon reaction of thecalcium oxide with water.
 17. The sealant composition of claim 1 whereinthe calcium oxide does not substantially react with or corrode othercomponents of the sealant.
 18. The sealant composition of claim 1wherein the olefinic polymer includes at least one of a polyethylene, apolypropylene, a polybutene, a polyisobutene, a butyl rubber(polyisobutene-isoprene), styrene block copolymers, and modified formsof styrene block copolymers, wherein the olefinic polymers have a numberaverage molecular weight of 100-700,000 Da, wherein the silane modifiedpolyolefins include at least one of an amorphous poly alpha olefin, asilane grafted PE, a moisture curing catalyst, an alkoxy silane, and anamino silane, wherein the fillers include at least one of a groundchalk, a precipitated chalk, a silicate, a silicon oxide, CaCO3,Ca(OH)2, and titanium dioxide, and wherein the silicate is selected fromthe group comprising talc, kaolin, mica, silicon oxide, silicas, andcalcium or magnesium silicates, and wherein the aging resistors includeat least one of hindered phenols, hindered amines, thioethers, mercaptocompounds, phosphorous esters, benzotriazoles, benzophenones, andantizonants.
 19. A solar module comprising: a first substrate; a secondsubstrate; at least one photovoltaic cell disposed between the first andsecond substrates; a sealant in contact with the first and secondsubstrates to form a moisture vapor barrier to hinder moisture vaporfrom reaching the at least one photovoltaic cell, wherein the sealantincludes: an olefinic polymer; a silane modified polyolefin; at leastone filler; a carbon black; a calcium oxide included in an amountgreater than about 2.5% by weight of the total composition; and at leastone aging resistor.
 20. The solar module of claim 19 wherein the sealantcomposition includes a molecular sieve included in an amount greaterthan about 2.5% by weight of the total composition.
 21. The solar moduleof claim 20 wherein a combination of the calcium oxide and the molecularsieve is included in an amount from about 10% to about 40% by weight ofthe total composition.
 22. The solar module of claim 20 wherein acombination of the calcium oxide and the molecular sieve is included inan amount from about 20% to about 40% by weight of the totalcomposition.
 23. The solar module of claim 20 wherein a combination ofthe calcium oxide and the molecular sieve is included in an amount fromabout 25% to about 35% by weight of the total composition.
 24. The solarmodule of claim 19 wherein the olefinic polymer is included in an amountfrom about 30% to about 60% by weight of the total composition, thesilane modified polyolefin is included in an amount from about 10% toabout 25% by weight of the total composition, the carbon black isincluded in an amount from about 2% to about 20% by weight of the totalcomposition, the filler is included in an amount from about 20% to about60% by weight of the total composition, the calcium oxide is included inan amount from about 2.5% to about 25% by weight of the totalcomposition, and the aging resistor is included in an amount up to about2% by weight of the total composition.
 25. The solar module of claim 20wherein the olefinic polymer is included in an amount from about 30% toabout 40% by weight of the total composition, the silane modifiedpolyolefin is included in an amount from about 10% to about 20% byweight of the total composition, a combination of the carbon black andthe filler is included in an amount from about 30% to about 40% byweight of the total composition, the calcium oxide is included in anamount from about 10% to about 30% by weight of the total composition,and the aging resistor is included in an amount up to about 2% by weightof the total composition.
 26. The solar module of claim 25 wherein thesealant includes a molecular sieve included in an amount from about 2.5%to about 25% by weight of the total composition.
 27. The solar module ofclaim 20 wherein the sealant composition exhibits less than about 15gm/((m̂2)*day) moisture vapor transmission rate at steady state for a0.030 inch thick sample of the sealant composition tested at 85 C and100% relative humidity.
 28. The solar module of claim 20 wherein thesealant includes balanced properties that keep swelling of the sealantto a predetermined amount upon reaction of the calcium oxide with water.29. The solar module of claim 20 wherein the calcium oxide does notsubstantially react with or corrode the sealant or the first and secondsubstrates.
 30. The solar module of claim 20 wherein the olefinicpolymer includes at least one of a polyethylene, a polypropylene, apolybutene, a polyisobutene, a butyl rubber (polyisobutene-isoprene),styrene block copolymers, and modified forms of styrene blockcopolymers, and wherein the olefinic polymers have a Number averagemolecular weight of 100-700,000 Da.
 31. The solar module of claim 20wherein the silane modified polyolefins include at least one of anamorphous poly alpha olefin, a silane grafted PE, a moisture curingcatalyst, an alkoxy silane, and an amino silane.
 32. The solar module ofclaim 20 wherein the fillers include at least one of a ground chalk, aprecipitated chalk, a silicate, a silicon oxide, CaCO3, Ca(OH)2, andtitanium dioxide, and wherein the silicate is selected from the groupcomprising talc, kaolin, mica, silicon oxide, silicas, and calcium ormagnesium silicates.
 33. The solar module of claim 20 wherein the agingresistors include at least one of hindered phenols, hindered amines,thioethers, mercapto compounds, phosphorous esters, benzotriazoles,benzophenones, and antizonants.
 34. A sealing compound for use in asolar module having a first substrate and a second substrate, whereinthe sealing compound is disposed between the first substrate and thesecond substrate, the sealing compound comprising: an olefinic polymerin an amount greater than about 30% by weight of the total composition;at least one of a silane modified APAO and a silane modified polymer inan amount less than 35% by weight of the total composition; a filler; acarbon black having a primary particle size of less than about 60 nm; acalcium oxide included in an amount greater than about 2.5% by weight ofthe total composition; a molecular sieve included in an amount greaterthan about 2.5% by weight of the total composition; and an agingresistor.
 35. The sealing compound of claim 34 wherein the olefinicpolymer includes a polyisobutylene in an amount from about 30% to about60% by weight of the total composition, the at least one of the silanemodified APAO and the silane modified polyisobutylene is included in anamount from about 2% to about 35% by weight of the total composition,the filler is included in an amount from about 3% to about 47% by weightof the total composition, a combination of the molecular sieve and thecalcium oxide is included in an amount of about 10% to about 40% byweight of the total composition, and the aging resistor is included inan amount from 0.1% to about 3% by weight of the total composition.